Home Node-Bs (HNBs) and Home e-Node-Bs (HeNBs), hereinafter collectively referred to as Home Node-Bs (HNB) may be used to increase cellular coverage and overall system throughput. These HNBs may have a dense deployment and be located in the coverage area of one or more macro (e)Node-Bs.
The term HNB may refer to a physical device that is similar to a wireless local area network (WLAN) access point (AP). The HNB may provide users with access to Universal Mobile Telecommunications System (UMTS), 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE), and other telecommunication services over small service areas, such as homes, retail businesses, or small offices. The HNB may connect to the operators' core network by using, for example, an internet connection (e.g., digital subscriber line (DSL)).
A HNB closed subscriber group (CSG) cell may be a determined area over which radio coverage provided by the HNB may be accessed by a group of subscribers authorized to use the services of the cell. These authorized WTRUs may be referred to as members of the CSG cell. The CSG may be a family or any user in the vicinity of a particular location, (e.g., anyone in a coffee shop), that attempts to access the HNB CSG cell. The subscriber, (e.g., an individual or an organization), may deploy a CSG cell using a HNB over an area where such service is desired. Each WTRU may store a white list (e.g., an allowed CSG list) which may include the CSG Identities (IDs) of the CSG cells it is authorized to access. When referred to hereafter, the term hybrid cell may include but is not limited to a cell that works like a CSG cell for member WTRUs and like an open cell for non-member WTRUs.
IDLE mode mobility (and states used for mobility e.g., IDLE, CELL_PCH and URA_PCH for UMTS, IDLE) describe procedures for when the WTRU may be using limited uplink resources. Connected mode mobility (e.g., CELL_DCH for UMTS) may include procedures for the WTRU when uplink resources are being more heavily utilized. Connected mode mobility for CSG cells may include a proximity indication wherein the WTRU may send a proximity indication message to the network if the WTRU determines that a possible allowed CSG cell is nearby. The WTRU may make this determination based on fingerprint match, which may include information the WTRU stores when it visits a CSG cell that is part of its white list. It may include information on the neighboring macro cells (e.g. PSC/Physical Cell Identity (PCI) of six macro cells) or localization information (e.g., GPS coordinates). The fingerprint information may include the PSC/PCI of the CSG cell.
Procedures for mobility between H(e)NBs and outbound mobility may be different than for inbound mobility. For example, in UMTS inter-frequency measurements may be triggered when the serving frequency quality falls below a predetermined threshold. If the network decides that inter frequency measurements need to be performed, the network may send control signaling. An event may also be signaled along with the measurements. For inter-frequency measurement a reporting event 2x may be used. For example, in UMTS, events that may trigger a Measurement Report may include: Event 2a: Change of Best Frequency; Event 2b: The estimated quality of the currently used frequency is below a certain threshold and the estimated quality of a non-used frequency is above a certain threshold; Event 2c: The estimated quality of a non-used frequency is above a certain threshold; Event 2d: The estimated quality of the currently used frequency is below a certain threshold; Event 2e: The estimated quality of a non-used frequency is below a certain threshold; or, Event 2f: The estimated quality of the currently used frequency is above a certain threshold.
Events 3x (e.g., 3a-3d) may be used for measurement control and reporting for inter-RAT handover.